Potential SharpRDP Behavior

Identifies potential behavior of SharpRDP, which is a tool that can be used to perform authenticated command execution against a remote target via Remote Desktop Protocol (RDP) for the purposes of lateral movement.

Rule type: eql

Rule indices:

logs-endpoint.events.process-*
logs-endpoint.events.registry-*
logs-endpoint.events.network-*

Severity: high

Risk score: 73

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

Domain: Endpoint
OS: Windows
Use Case: Threat Detection
Tactic: Lateral Movement
Data Source: Elastic Defend

Version: 108

Rule authors:

Elastic

Rule license: Elastic License v2

Rule query

edit

/* Incoming RDP followed by a new RunMRU string value set to cmd, powershell, taskmgr or tsclient, followed by process execution within 1m */

sequence by host.id with maxspan=1m
  [network where host.os.type == "windows" and event.type == "start" and process.name : "svchost.exe" and destination.port == 3389 and
   network.direction : ("incoming", "ingress") and network.transport == "tcp" and
   source.ip != "127.0.0.1" and source.ip != "::1"
  ]

  [registry where host.os.type == "windows" and event.type == "change" and process.name : "explorer.exe" and
   registry.path : ("HKEY_USERS\\*\\Software\\Microsoft\\Windows\\CurrentVersion\\Explorer\\RunMRU\\*") and
   registry.data.strings : ("cmd.exe*", "powershell.exe*", "taskmgr*", "\\\\tsclient\\*.exe\\*")
  ]

  [process where host.os.type == "windows" and event.type == "start" and
   (process.parent.name : ("cmd.exe", "powershell.exe", "taskmgr.exe") or process.args : ("\\\\tsclient\\*.exe")) and
   not process.name : "conhost.exe"
   ]

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Lateral Movement
- ID: TA0008
- Reference URL: https://attack.mitre.org/tactics/TA0008/
Technique:
- Name: Remote Services
- ID: T1021
- Reference URL: https://attack.mitre.org/techniques/T1021/
Sub-technique:
- Name: Remote Desktop Protocol
- ID: T1021.001
- Reference URL: https://attack.mitre.org/techniques/T1021/001/

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